Just picked up a 04 Mazda RX8 with 54,000 km (not miles) and found out Mazda has extended the powertrain warranty to 8 years/160,000 km. Great except for the fact that the last owner did not keep any oil change receipts although he claimed to have changed it every 5,000 km.

I intend to keep very meticulous records from here on. If something were to go wrong, how could I prove that it was not a maintenance related issue? Is the visual difference between a well kept engine and a abused rotary quite different? Or, does a blown rotary look the same whether it was well kept or abused?

From what I've been able to gather, the weakest link in that engine is the apex seals. They're vulnerable to oil starvation and are said to also deteriorate quickly with the use of synthetic oil. The techs know what to look for when this is the failure point.

To be completely honest, the rest of the engine seems to be quite robust. Apex seals are the only failure I've read about on the Mazda forums I frequent.

My question is...did Mazda extend the warranty on THAT SPECIFIC car, or all RX-8s? That could mean very different things depending on what the answer is.

Since the car is in good running condition at the time you took ownership, I wouldn't worry about the previous owner's lack of recordkeeping. Just keep your own records and be ready to present them if a problem arises. To avoid future problems, use a good quality conventional oil and keep your eye on the oil level. These engines are designed to consume it. People who never crack the hood open between OCIs are the ones you'll find waiting at the dealership for a new engine.

I guess it would just help me sleep better at night knowing that I would be covered if anything happened.

"Mazda's warranty coverage on the rotary engine has been increased to eight years or 160,000 kilometres. Mazda has also retroactively extended this warranty coverage to all 2004-2008 model years of the RX8."

In the US the manufacturers generally have to prove the customers neglected the change intervals, so you're innocent until proven guilty. If you have records from day one of your ownership I see you in great shape.

In the US the manufacturers generally have to prove the customers neglected the change intervals, so you're innocent until proven guilty. If you have records from day one of your ownership I see you in great shape.

Here's what I do, and yes it sound dorky. I take the empty oil bottles after each change and take a digital picture of them with a date/time stamp displayed. I take one more picture of the oil draining into the oil change pan. For the oil filter, I cut the box into a nice square and write a date and mileage on it with a sharpy and file it. I also do it with air filter boxes.

GM has an on-line "Owner's Center" site. One thing that owners can do is log the maintenance that has been performed, on their own page at the site. Not sure if any other manufacturer does this as well.

I use this as my "official records", as I do all the maintenance on my vehicle.

If there's any question, it's right there.

This site also notifies me of any recalls, and other issues as well.

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Whatever you do... do NOT speed through the town of Gauley Bridge, WV.

At this point, there's no reason to worry about it until something happens. Unless the engine truly was abused, you're unlikely to have a lubrication-related failure. Something breaking due to a manufacturing defect is more likely. But if you do, I think you can expect that they won't warranty it. That's a chance you take when buying a used vehicle without maintenance records.

If there is an engine problem, the dealership or someone at a higher level would have to determine that the engine oil caused the problem, in order to deny warranty coverage.

In that case, with receipts you may be able to collect from the company that produced the engine oil. Most of them offer an implicit or explicit warranty -- if their oil wrecks your engine, they pay for the repairs or replacement.